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Taking the whole "adapt or you're road kill" thing rather literally. In the US, motor vehicles are killing about 80 million birds each year, the sort of figure that evolutionary biologists would call "selective pressure." And now, in a paper entitled "Where has all the road kill gone?", some researchers have gone out and confirmed that at least one bird population is experiencing an evolutionary response. Death-by-auto has been declining among the cliff swallows of western Nebraska for 30 years, and the researchers found that the bodies left behind after hit-and-runs had longer wings than the population as a whole. They conclude that the swallows wings are, on average, getting shorter to help them respond more quickly to oncoming traffic.

Diagnosis by text message, or "u r having a stroke." Medical authorities have become excited about the use of text messages, but mostly as an intervention—short reminders have been found to help people stay on their medications, or quit smoking. But a recent case study showed that, in rare circumstances, they be a diagnostic tool. Strokes tend to strike very specific areas of the brain, leaving surrounding ones functioning normally, which makes them hard to spot. In one case, a 40 year old male had symptoms of a stroke but could speak just fine. However, his texts had some serious issues, as they consisted of things like "Oh baby your;" and "Tjhe Doctor nddds a new bb."

Doctors are apparently calling this "dystextia," meaning "incoherent text messaging that can sometimes be confused with autocorrect garble."

Sharing a hard elbow and a bit of your microbiome. The ability to sample large bacterial populations has allowed us to get a much better grip on the bacteria living on and in our bodies (we each walk around carrying more bacterial cells than human ones). And these studies are indicating that each of us is a distinctive ecosystem, with our own collections of species and populations. But how do we manage to pick up all that diversity in the first place? A new study suggests one option: rollerderby. Researchers showed that, prior to an all-day tournament, each team started out with its own community of bacteria, which was somewhat similar among teammates. Over the course of a game, however, the two teams' microbiota started to be shared along with their sweat. They think that the same is probably true for any other contact sport, and for human contact in general.

You may feel better, but it's probably not good for you. Aside from porn and cats, the Internet seems to be made for rants. People find venting their outrage so cathartic that sites have been set up that are dedicated to hosting bile-filled rants on a variety of topics. Fortunately, a pair of researchers from Green Bay Wisconsin are here to tell you that the positive effects of catharsis may have their limits. People who chose to participate in a laboratory-supervised rant tended to fall into two categories: one that felt better after having had their say, and another that ended up even angrier than they were at the start.

Among those who enjoyed ranting, however, there were a number of signs of anger management issues, including (on average) at least one physical altercation per month and two shouting matches in the same period. About half had been told they had an anger problem. So, the study seems to indicate that people are either going to dislike rant sites or, if they find themselves enjoying posting on them, are probably having general issues with self-control.

Knowledge is overrated. People like to gamble on sports for a variety of reasons, but one of them is an sense of control—we think our knowledge of the game and teams involved can help us do better than we would in a pure game of chance, like craps. According to a study of people asked to bet on soccer, however, that sense of control is an illusion. The study involved three groups of people: professional gamblers, soccer fanatics, and a control group that was indifferent to the sport. In the end, the two best performances came out of the control group, which, as a whole, performed just as well as the gamblers and soccer fans.

It's a news summary of interesting tidbits that you probably didn't hear about from the world of science this week, presented to you in a humorous form. They've been writing them this way for years and I wouldn't have it any other way!

Much of our usual appreciation of an animal - in any condition - depends on our ability to identify and name it. For flattened fauna, however, that can be a problem. Most of these animals have been pressed to the road for several days and may have assumed unrecognizable shapes. This book is devoted to making the experience of seeing dead animals on the road meaningful, even enjoyable.

I have noticed that squirrels in my area are much less likely to hesitate on the road when a car is approaching than they used to (and fewer squished ones, even though squirrel populations are still high). It seems the hesitant ones have not passed on their genes as frequently as the more decisive squirrels.

As the swallows' wings become shorter, I wonder what the trade-off is. Shorter wings help them avoid the traffic, but wouldn't their previously longer wings have evolved to give them some other advantage?

It's very interesting that we (humans) are actively putting evolutionary pressures on other species.

Spazmodica wrote:

As the swallows' wings become shorter, I wonder what the trade-off is. Shorter wings help them avoid the traffic, but wouldn't their previously longer wings have evolved to give them some other advantage?

I'd guess that longer wings would help conserve energy while flying, so possibly less frequent feeding needed. But shorter wings would help the birds to grab more, smaller "meals".

I imagine we do not know about the swallows but as speculation: longer wings make migration more efficient through lower energy output. Your final essay question for your biology degree:Design an experiment(s) to test sucha hypothesis and suggest another to look at the survival advantage of long wings in migration.Nature Lover

Hah! My conservative parents have asked me why we don't see evolution because of roadkill, and I've always said I was sure it was occurring, but perhaps too slowly to notice, and here is the evidence. Sweet!

Would shorter wings make it easier or more difficult for them to carry a coconut?

These are Nebraskan swallows. The coconut-carrying variety is well known to be African. The smaller European variety has long since been shown to be incapable of enabling coconut migration, which likely would then imply that the Nebraskan cliff swallow would be limited to much smaller, presumably immature coconuts. Although if they are evolving fast enough, perhaps they can nonetheless cooperatively grip the husk and attain the necessary lift.

Natural Selection =/= Evolution. I've been reading this story at a variety of sources, and while the headlines keep saying "evolution," the data clearly states it has been a result of natural selection. Same old birds as before, just the ones better suited for avoiding cars have made the cut. The birds' genetic code has not changed whatsoever from what I've witnessed the research state.

I've been reading this story at a variety of sources, and while the headlines keep saying "evolution," the data clearly states it has been a result of natural selection. Same old birds as before, just the ones better suited for avoiding cars have made the cut. The birds' genetic code has not changed whatsoever from what I've witnessed the research state.

Evolution is the change in allele frequency in a population over time. As this population experiences the selective pressure where longer-winged, less agile birds are killed off, the population's gene pool shows and higher and higher representation of the shorter-winged type. Not just because the individuals with longer wings are more likely to die, but because this makes them less likely to breed at a comparable rate to the now more-numerous shorter-winged type. Thus the alleles (what we tend to think of as "genes") experience both the effect of individuals losing out and the knock-off effects of the more 'fit' Team Shortwing reproducing more successfully in comparison. That's evolution.

What, did you expect them to turn into griffons? Spontaneously mutate into car-smashing bird-hulks?

Not quite. Here's the actual definition (from google):ev·o·lu·tion - noun1. The process by which different kinds of living organisms are thought to have developed and diversified from earlier forms during the history of the earth2. The gradual development of something, esp. from a simple to a more complex form.

BY DEFINITION, evolution causes diversification and increased complexity, right? Natural selection on the other hand, weeds out poorly adapted ones. If anything, genetic code is lost over time with natural selection, nothing new is gained. The long winged birds are dying out. The short winged ones are making it. Nothing has changed, except the loss of a variation. We are NOT observing diversification and increased complexity with these birds. We are seeing a simplification of the species in this instance.

I understand what you're saying about the more successful allele sets being the ones to perpetuate, but that IS natural selection. Sure, the allele frequencies can change, just as with easily changeable variations in dogs and cats, but no NEW genes are created. Take away our selective breeding of dogs, and throw them all into the wild, and these multiple breeds would eventually morph back into a more homogeneous species. Same would go for humans if borders and racism didn't exist. We would LOSE genetic diversification. If anything, what's being observed with these birds is the OPPOSITE of evolution, as they are NOT diversifying the species.

Scientists are so quick to point at these observable variations as instances of evolution, but until we observe new genes tacked on (not just minor changes in the allele frequency), it is simply natural selection. Nothing more. I love science, but we need to remain intellectually honest here if we're going to truly advance the field.

No. The dictionary definition may imply that, but that is not true. The scientific definition of biological evolution is exactly what Wheels said: Change in allele frequency over time. Evolution does not necessarily result in diversity -- however it does explain how diversity is possible.

Natural selection is one of the mechanisms by which this occurs. Natural selection is an aspect of evolution, not a separate thing. "This is natural selection, therefore not evolution" is incorrect. "This is natural selection, therefore evolution" is correct.

Quote:

Sure, the allele frequencies can change, just as with easily changeable variations in dogs and cats, but no NEW genes are created.

Okay, this sounds just the 'micro/macro' thing with those words replaced with "natural selection" and "evolution" when that's not what they mean.

In any case you're just mistaken -- new genes crop up all the time. How do you think the alleles for shorter wingspans got into the swallow gene pool in the first place so that they could subsequently be selected for more strongly once cars showed up?

And in dogs or cats -- mutations arise naturally in dog and cat populations, and entire breeds are based around selecting for those mutations. E.g. there is a mutation in cats that causes their spines to not fully develop. Cats that are heterozygous for this gene have short, stumpy tails. Cats that are homozygous don't get a full spinal column and are still-born. Neither trait is selected for in the wild, ergo seeing such cats at random is rare. However it could be selected for either via an artificial population bottleneck on the Isle of Mann or via the selection via modern breeders, we have the Manx breed known for being tailless.

If you released all these cats and dogs back into the wild, the selective pressure would be strongly against Manx-ness, and either against or not selective for most other traits they are bred for, and so you'd see them slowly revert back towards the usual rates of this mutated allele.

New mutations would continue to arise, but most would be selected against, and so you wouldn't notice unless you were really studying them.